How to Change employer Before Start Date of October 1st for H1B visa

I am a H4 who got a H1B this year 2014. But, my employer has not found me a job yet and I getting close to Oct 1st 2014.

Will I be out of status on Oct 1st ?

Can my employer cancel my visa before Oct 1st? How about after Oct 1st if I do not find a job?

Also, can I transfer my visa before Oct 1st and how do I do this?

Please advice.